This invention relates to that class of beverage dispensing machine that is characterized by a transparent beverage supply tank atop a base and having a manually accessible dispensing valve by which beverage in the beverage tank can be dispensed a serving at a time. This class of machines is ordinarily set atop a service counter where beverages are sold and dispensed and so that the beverage in the beverage tank is displayed to entice customers.
The above-noted class of beverage machine was originated in the 1920s when ordinary water cooler structures including inverted five-gallon water bottles set atop stands were utilized to display and dispense noncarbonated beverages. Those early machines were found to take up too much space, required premixing beverages in supplies of beverage bottles and required frequent manual replacement of empty beverage bottles with full beverage bottles.
Throughout the ensuing years, there has been a continuous effort on the part of those skilled in the art to reduce those shortcomings and inconveniences associated with the manufacture, use and maintenance of such machines and to enhance all of the desirable aspects thereof.
As of this date, the above-noted class of machines has evolved to include extremely neat and attractive counter-top machines with one- or two-gallon beverage supply tanks. The machines include mixing heads adjacent the beverage tanks and connected with remote water and beverage concentrate or syrup supplies by means of elongate water and syrup lines or hoses. The mixing heads are controlled by liquid-level sensing devices in the beverage tanks and function to deliver correctly metered volumes of water and syrup into the tanks to make beverage therein and to maintain the level of beverage in the tanks at or between attractive levels.
The above-noted state-of-the-art machines take up little counter space, operate to cool and to effectively display the beverages dispensed thereby; and, operate to maintain the tanks substantially full at all times, until the supplies of syrup are exhausted.
In recent years, the manufacturers and suppliers of beverage concentrate syrups have provided syrups in various kinds and sizes of containers with the view of making the supplying and handling of those syrups more convenient and cost-effective. Most recently, attention has been given to the supplying of syrup in large volume tanks (syrup tanks) that can be pressurized with CO.sub.2 gas to effect transfer of the syrups from the tanks, through syrup hoses or lines, to the mixing heads of related machines. The use of such pressurized tanks is proving to be highly favored since most places where beverage dispensing machines of the class here concerned with are used also make and sell carbonated beverages (such as colas) and are equipped with CO.sub.2 gas cylinders that can be most conveniently used to pressurize the syrup tanks. With the noted gas-pressurized syrup tanks, the beverage dispensing machines need not be provided with those special, costly and oftentimes inconvenient to use and maintain syrup transporting and/or pumping devices that are otherwise required to effect the transporting of syrup from remote syrup supplies to the machines.
The principal shortcoming that has been experienced with the use of pressurized syrup supply tanks resides in the fact that when the syrup tanks are empty the machines continue to operate to deliver notable volumes of water into the beverage tanks of the machines without corresponding volumes of syrup. When the foregoing occurs, the beverages in the beverage tanks are diluted with water and are rendered unmerchantable and such that they must be disposed of. Further, when empty syrup tanks are replaced with new or full tanks and the machines are put back into operation, the machines only deliver water into the beverage tanks until the syrup lines extending from the syrup tanks to the mixing heads of the machines are once again filled with syrup or primed. In a great number of situations, the syrup lines are of sufficient length and of such volumetric extent that before syrup has flowed from the syrup supply tanks and reached the mixing heads, sufficient volumes of water have flowed into the beverage tanks to dilute the beverages therein to an extent that they must be disposed of. When this occurs, the machines must be put out of service and worked upon a sufficient period of time to effect draining and disposal of diluted beverages and that further period of time that is required for the machines to make and refill the beverage tanks with vendable supplies of properly constituted beverages. The wasted service time and the waste of product experienced in furtherance of the foregoing are costly and are of great concern to the owners and operators of beverage dispensing machines.
It is understood that in efforts to overcome the above-noted problems and/or shortcomings experienced in the use of pressurized syrup supply tanks in combination with the class of beverage dispensing machines here concerned with, some persons skilled in the art have proposed the adding and use of special valves and the exercise of special operating procedures to effect priming of the syrup hoses with syrup before the machines are put into regular operation and to thereby prevent the making of diluted beverages that must be disposed of, as noted above. It is understood and believed that those special operating procedures that must be exercised to effect priming the syrup lines with syrup prior to putting the machines into operating service are not only time-consuming but are procedures that, if followed at all, are likely to be exercised improperly by those persons who are normally charged with the maintenance and operations of such machines.
It is to be noted that some prior art machines are equipped with syrup-sensing devices at the syrup inlets of their mixing heads and/or at the downstream ends of the syrup hoses that operate to turn the machines off and stop operation thereof when their related syrup supplies are exhausted and to thereby prevent dilution of beverages in the beverage tanks by continued flow of water into them. It is to be further noted that such syrup sensing devices do not operate to prevent the syrup lines, downstream of the machines, from being purged and emptied of syrup when the supplies of syrup for the machines are exhausted and are not operable to effect refilling or priming of the syrup lines with syrup when the machines are first put back into operation and before water is caused to flow into the beverage tanks in a manner to cause dilution of beverage therein.